The present application claims priority under 35 USC 119 to Japanese Patent Application No. 2000-244320 filed on Aug. 11, 2000 the entire contents thereof are incorporated by reference.
1. Field of the Invention
The present invention relates to a rear wheel supporting device for a vehicle for supporting a rear wheel at the rear of a vehicle body frame.
2. Description of Background Art
In a rear wheel supporting device for a vehicle, for example, two- and three-wheeled vehicles, a swing member is vertically swingably attached at the rear of the vehicle body frame. A rear wheel is rotatably mounted on the rear portion of the swing member. A rear wheel supporting device for a vehicle, is known as disclosed in, for example, Japanese Patent Laid-Open No. Hei 1-175590 Chain Adjuster of Motorcycles (hereinafter called xe2x80x9cthe prior artxe2x80x9d).
According to FIGS. 1 and 2 of Japanese Patent Laid-Open No. Hei 1-175590, a through hole is formed in the direction of a vehicle width in the rear portion of the frame 2 (the numerals used herein are the same as the numerals used in the prior art). An eccentric cam 12a is rotatably installed in the through hole. In the eccentric cam 12a is formed a shaft hole 13 which is off-center in the radial direction, and a pivot 3 of a rear swing arm 1 is rotatably installed in the shaft hole 13. Then, the rear swing arm 1 is vertically swingably installed at the rear portion of the frame 2. At the rear of the rear swing arm 1 is rotatably mounted a rear wheel 4.
According to the prior art described above, the mounting height of the pivot 3 in the rear swing arm 1 can be adjusted by turning the eccentric cam 12a. However, the adjustable range of the mounting height of the pivot 3 is very narrow, that is, within the range of an amount of the off-center of the shaft hole 13 formed in the eccentric cam 12a. 
In a general motorcycle, the rear wheel is subject to a change in diameter depending upon the vehicle type from the viewpoint of commonality of the vehicle frame. With a change in the diameter of the rear wheel 4, the mounting height (ground clearance) of the pivot 3 varies. The adjustable range of the mounting height of the pivot 3 in the prior art stated above is very narrow and cannot be properly adjusted. To widen the adjustable range, it is necessary to increase the amount of the off-center of the shaft hole 13, which, however, will result in an increased diameter of the eccentric cam 12a, giving an effect to the shape and size of the frame 2 on which the eccentric cam 12a is mounted. The frame 2, therefore, will require a change. That is, every time the diameter of the rear wheel 4 is changed, the frame 2 is also changed. There is, therefore, a necessity to improve the rear wheel supporting device to reduce the cost of the vehicle, such as two- and three-wheeled vehicles.
It is, therefore, an object of the present invention to provide a support device capable of commonly being used with a vehicle body frame even in the case wherein the rear wheel diameter is changed.
According to the present invention, for attaining the object stated above, the rear wheel supporting device for the vehicle has a pivot member removably installed at the rear portion of the vehicle body frame, a swing member is vertically swingably attached to the pivot member, and a rear wheel is rotatably mounted at the rear portion of this swing member. The rear wheel supporting device is characterized by vertically arranging a plurality of joining portions on at least either one of the vehicle body frame and the pivot member, thereby enabling free adjustment of the mounting height of the pivot member.
According to the above-described structure, the mounting height of the pivot member can be freely adjusted by selecting the plurality of vertically arranged joining portions in accordance with the diameter of the rear wheel and attaching the pivot member. As a result, the mounting height of the swing member can be freely adjusted. Therefore, it is possible to commonly use the vehicle body frame and the swing member if the rear wheel diameter has been changed.
According to the present invention, in the rear wheel supporting device for a vehicle, the pivot member is removably attached at a rear portion of the vehicle body frame, the swing member is vertically swingably attached on the pivot member, and the rear wheel is rotatably mounted at the rear of the swing member. The rear wheel supporting device has, at the pivot member, the first and second joining portions in at least two points, upper and lower, for joining the rear wheel supporting device to the vehicle body frame, and a pivot point is located in a position close to the first joining portion above the middle height of said first and second joining portions, so that the height position of the pivot point may be altered by turning the pivot member upside down.
The height position of the pivot point can be changed by attaching the first and second joining portions to the vehicle body frame with the pivot member turned upside down in accordance with the diameter of the rear wheel. Consequently, it is possible to freely change the mounting height of the swing member. Therefore the vehicle body frame and the swing member are commonly usable if the diameter of the rear wheel is altered.
According to the present invention, in the rear wheel supporting device for a vehicle, the pivot member is removably attached at a rear portion of the vehicle body frame, the swing member is vertically swingably attached on the pivot member, and the rear wheel is rotatably mounted at the rear of the swing member. That is, the pivot member is attached on the rear surface of the vehicle body frame.
The pivot member can be installed to the vehicle body frame in such a manner that it will be removable from the rear.
The prior art stated above is of such a configuration that the eccentric cam 12a is rotatably installed in a hole formed in the direction of vehicle width in the frame 2; and the pivot 3 of the rear swing arm 1 is rotatably installed in the off-center shaft hole 13 of the eccentric cam 12a. If the range of the mounting height of the pivot 3 is widened, the eccentric cam 12a increases in diameter, therefore affecting the shape and size of the frame 2 on which the eccentric cam 12a is mounted.
According to the present invention, however, the pivot member is installed from the rear to the rear surface of the vehicle body frame; therefore, the vehicle body frame will be slightly affected if the range of the pivot member mounting height that is freely set. It is, therefore, possible to commonly use the vehicle body frame if the rear wheel diameter is changed.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.